In recent years, slide-style mobile devices have become popular in the wireless industry. Typically, a slide-style device includes a fixed base portion and a movable slide portion, and when the slide portion is moved, one or more hidden features or components may be accessed. As an example, many slide-style devices include a physical keypad that is hidden underneath the slide portion when the device is in a closed state but that can be used when the slide portion is moved and the device is in an open state. This configuration also allows for a relatively large display to be implemented into the device.
The slide portion generally includes various components, such as a display, a camera or other electronic lines, that need to reach the main printed circuit board (PCB). The main PCB, however, is normally built into the fixed base portion. To accommodate this need, a flexible circuit—a flexible substrate that contains embedded signal traces—is attached to the main PCB and can be fed to the relevant connections in the slide portion.
Referring to FIG. 1, an example of a prior art slide-style mobile device 100 is shown. The device 100 includes a fixed base portion 105 and a movable slide portion 110, which is slidably coupled to the base portion 105. In this view, a back side 115 of the base portion 105 can be seen. A top surface 120 of the base portion 105 is also shown here. In this model, the slide portion 110 includes a slide plate 125, which is generally a piece of sheet metal. The slide plate 125 is used for providing support for the components that are part of the slide portion 110. This particular arrangement in FIG. 1 shows the mobile device 100 in an open position in which components on the lower front surface (not shown) of the base portion 105 can be accessed.
Referring to FIG. 2, a transparent view of the slide plate 125 (shown with a dashed outline) is pictured. The components of FIG. 2 are integrated into the mobile device 100 of FIG. 1. In this view, a front surface 205 of the slide plate 125 faces an operator of the mobile device 100 when, for example, the operator would be looking at a display (not shown) that would be integrated with the slide portion 110. A fixed guide base 210, which is part of the base portion 105 and is slidably coupled to the slide plate 125, is also illustrated. From this vantage point, the slide plate 125 is positioned above the guide base 210. A planar surface 215 that is positioned just above the slide plate 125 and the guide base 210 represents the top surface 120 of the base portion 105 from FIG. 1. A flexible circuit 220, which relays signals between the main PCB (not shown) and components (not shown) in the slide portion 110 is also depicted. The slide plate 125 contains a slot 225 (also has a dashed outline), and the guide base 210 also includes a slot 230, both of which are for accommodating the flexible circuit 220. In this drawing, the slide plate 125 and the guide base 210 are in a closed position, meaning that the base portion 105 and the slide portion 110 are aligned with one another.
Referring to FIG. 3, the slide plate 125 (and hence the slide portion 110 of FIG. 1) has been moved in the vertical direction away from the guide base 210, which indicates an open position. Because it is flexible, the flexible circuit 220 has also moved in this same direction, which allows for the uninterrupted transfer of signals between components of the base portion 105 and the slide portion 110 in this open position. The configuration of the slot 225 of the slide plate 125, however, presents a significant drawback. Notably, the surface of the slide plate 125 that is opposite the front surface 205 can be seen by the operator of the mobile device 100 when the device 100 is in the open position. As such, the operator can see the slot 225 and the flexible circuit 220, which degrades from the overall appearance of the device 100. The portion of the slot 225 that is visible in this state can also be seen in FIG. 1 (see the section with the diagonal hatching). In addition to negatively affecting the visual aspects of the device 100, the slot 225 also presents an open pathway for dirt, water or other contaminants to enter the device 100 when the device 100 is in the open position.